Method for repairing pipings

Abstract

The invention relates to a method for sealing and repairing a leaking and / or damaged area of a piping inner wall, wherein the piping is filled with a volume-expandable bellows structure and a curable material, and the bellows structure and the curable material are milled out in a subsequent step.

Description

Pipeline repair procedures Description

[0001] The present invention relates to a method for sealing and repairing a leaking and / or damaged area on an inner pipe wall of a pipeline.

[0002] The method is particularly suitable for the trenchless rehabilitation of defective, inaccessible pipelines, such as defective sewer lines. However, the method is not limited to a specific type of pipeline or a specific area of application. A pipeline is a hollow body through which a gaseous, liquid, or viscous fluid, or a solid-liquid mixture (e.g., wastewater), can be transported along a predetermined route. Pipelines are used in private households, in public drinking water supplies, wastewater treatment plants, and in industrial plants. This method can be used with pipes made of various materials, such as metal, ceramic, or plastic.

[0003] Various methods for sealing and repairing leaky and / or damaged areas on the inner wall of a pipeline are already known in the prior art, in particular the pipe-in-pipe method, in which a pipe with a diameter smaller than that of the existing pipe is pulled or pushed into the existing pipe until it lies over the leaky and / or damaged area on the existing pipe. However, this method has the disadvantage that it regularly leads to a reduction in the pipe cross-section in the area of the newly inserted pipe and that deposits can form on the edge of the inserted pipe. In addition, this This method can only be used for straight pipelines. Finally, a reliable seal between the two pipes is not guaranteed, so liquid or gas can escape between the interlocking pipes through the damaged and / or leaking point in the pipeline.

[0004] Another known method is the pipe bursting method, in which a hydraulic expander is inserted into the existing pipeline. Its expansion causes the existing pipe to rupture, and a new pipe is then inserted into the space created. However, this method does not guarantee that the structures surrounding the pipe wall will not be damaged if the existing pipe wall ruptures. It is also difficult to adequately seal the areas between the remaining existing pipe and the newly inserted pipe.

[0005] WO1995 / 027167A1 discloses a method in which a sewer rehabilitation robot has a carrying device in which a viscous sealant is applied to the leaking and / or damaged area. The sealant is then pressed against the inner pipe wall via an expandable expansion body. After curing, the expansion body contracts and is removed from the pipeline. This method has the disadvantage that the applied sealant settles on the inner pipe wall, thereby narrowing the cross-section of the pipeline. Here, too, deposits can form, particularly in the area of the applied sealant in sewer lines, and clog the pipeline.

[0006] Furthermore, methods are known in the prior art, for example from DE 10 2020 206 094 A1, in which a flexible lining tube impregnated with a curable resin is inserted into the pipeline as a liner. After insertion, the lining tube is expanded so that it fits tightly against the inner wall of the pipeline and presses the lining tube impregnated with the curable resin against the inner pipe wall. After the resin has cured, the lining tube can then be removed from the pipeline.

[0007] DE 10 2020 106 094 A1 describes how an inflatable rubber bellows is mounted on a rehabilitation packer that can be moved or slid within the pipe. Resin-impregnated rehabilitation mats are arranged on the outer circumference of the rubber bellows, which can be pressed against the inner wall of the pipe when the rubber bellows is inflated, where they harden. Furthermore, the resin can be Pressing the repair compound against the inner pipe wall allows it to penetrate cracks or open areas in the pipe. After removing the repair packer and rubber bellows, the repair compound and the resin remain at the previously leaking and / or damaged area of the pipe. With both of the above-mentioned pipe repair methods, the cross-section of the existing pipe is also reduced, as the sealant is deposited flatly on the inner pipe wall. The sealant thus causes adhesions to form in the area of the repaired area, which can then clog the pipe.

[0008] Finally, WO2021 / 063448A1 discloses a device comprising a storage container for PU material and a discharge opening. In this method for repairing pipelines, the device is inserted into the pipeline until the discharge opening is located in the area of the leaking and / or damaged part of the pipe wall. The PU material is then pressed from the storage container through the discharge opening against the inner pipe wall.

[0009] In another method, WO2021 / 063448A1 proposes that a cover element be arranged on a movable support element, by means of which the PU material is pressed between the cover element and the inner pipe wall. This method also inevitably leads to a cross-sectional constriction within the pipeline, which leads to the problems described above. In addition, damaged pipe sections, root intrusions, or other foreign bodies remain within the pipeline.

[0010] The present invention is therefore based on the object of providing a method for sealing and repairing a leaky and / or damaged area on the inner wall of a pipeline, in which the cross section of the pipeline is not narrowed even after the repair.

[0011] Furthermore, the present invention is based on the object of providing a reliable and robust method for sealing a leaky and / or damaged area on the inner wall of a pipeline, in which foreign bodies such as damaged pipe parts, root growth or other deposits are reliably removed from the pipeline.

[0012] Furthermore, the present invention is based on the object of filling and sealing cavities located outside the pipeline in the area of the leaking and / or damaged area.

[0013] The above objects are achieved according to the invention by a method with the features of claim 1. Advantageous embodiments and further developments of the method are disclosed in subclaims 2 to 14.

[0014] The present invention relates to a method for sealing and repairing a leaky and / or damaged spot on the inner wall of a pipeline, in which a volume-expandable bellows body is first provided, the bellows body is introduced into the pipeline until it is behind the area of the leaky and / or damaged spot, ie again in an area where the inner wall of the pipe no longer has any leaks and / or damage.

[0015] A leak, within the meaning of the present invention, is a location on the inner wall of a pipeline through which either the pipe contents can escape from the pipeline or foreign matter can penetrate the pipeline from the outside. A damaged location, within the meaning of this invention, includes leaks, but can also refer to damage in its early stages, e.g., a longitudinal or transverse crack in the inner wall of the pipe, which has not yet led to a leak in the pipeline.

[0016] In the context of the present invention, a volume-expandable bellows body is understood to be a body whose volume can expand upon the introduction of a substance. The volume expansion can occur isotropic or anisotropic (e.g., along a preferred direction). In a cylindrical bellows body with a circular cross-section in a pipeline, the volume expansion occurs primarily in the radial direction, i.e., toward the inner pipe wall. However, the expansion can also occur in all other spatial directions, i.e., both radially and along the bellows body. The bellows body is preferably made of an expandable or elastic material.

[0017] The bellows body should be leak-tight and mechanically robust, as well as abrasion-resistant to solids. It should contain any substances introduced into the pipe and ensure that the bellows body is not damaged by the pipe's inner wall and / or the solids contained therein when inserted into the pipe.

[0018] When inserting the bellows body into the interior of the pipeline, it should be advanced until it has completely passed the leaking and / or damaged area. The distance between the leaking and / or damaged area and the position of the bellows body should preferably be approximately 10 cm.

[0019] The bellows body should be positioned inside the pipeline in such a way that the leaking and / or damaged area on the inner pipe wall is freely accessible and can then be worked on.

[0020] In a third step, after the bellows body has been positioned as described above, a hardenable substance is introduced into the bellows body. The volume of the hardenable substance should be sufficient to bring the bellows body into full contact with the inner wall of the pipeline. The contact between the bellows body and the inner wall of the pipeline should be sufficient to seal the pipeline. In the context of the present invention, "sealing" refers to closing the pipeline so that substances from the area in front of the bellows body cannot penetrate into the area of the pipeline behind the bellows body.

[0021] The curable material within the meaning of this invention can be any material that is initially liquid, foam-like, or pasty and that solidifies over time with or without the influence of air, water, or chemical substances. According to the invention, the solidification of the material must result in the pipeline being sealed in the area of the bellows body. After the material has cured, the bellows body should close the pipeline. Depending on the chemical composition of the curable material, the material in the bellows body can cure either over time and / or with the addition of air, water, or other chemical substances that enable and / or accelerate the curing process of the material.

[0022] Only when the material in the bellows body has hardened and the pipeline is sealed by the bellows body, a curable material is introduced into the interior of the pipeline until the area between the bellows body and the leaking and / or damaged area in the pipeline is at least completely covered and filled. This can be the same curable material that was introduced into the bellows body or a different curable material suitable for completely sealing and / or repairing the leaking and / or damaged area on the inner pipe wall.

[0023] The curable material should be introduced into the pipeline until the area between the bellows body and the leaking and / or damaged area in the pipeline is at least completely covered and filled. Preferably, enough material should be introduced to also fill an area approximately 10 cm in front of the leaking and / or damaged area in the pipeline.

[0024] By introducing the hardenable substance, it penetrates through the leak into the area outside the pipeline and thus largely fills any cavities in this area as well. This ensures that the pipeline is also protected from further external influences in this area. In addition, the hardenable substance completely encloses any solids that have penetrated inside the pipeline, such as roots, stones, or soil. The hardenable substance distributes itself around these solids within the pipeline and embeds them. Therefore, once the substance has hardened, the solids can no longer move into this area of the pipeline's interior.

[0025] Once the material has hardened, the entire area between the bellows body and the leaking and / or damaged area is completely filled and sealed.

[0026] In the next step, a milling cutter is inserted into the interior of the pipeline. According to the invention, the milling head of this milling cutter ideally has a diameter that corresponds to the diameter of the pipeline. However, milling heads with a diameter smaller than the pipeline can also be used. With such an embodiment, however, care must be taken to ensure that the curable material in the pipeline and the bellows body are milled out in the final step to such an extent that no cross-sectional constriction occurs in this area of the pipeline. After milling out the cured material and the bellows body, the inner wall of the milled area should be smooth and similar to the inner wall of the rest of the pipeline.

[0027] As a result of the milling process, both the hardened material, as far as it lies within the pipeline, and the inserted bellows body with the hardenable material contained therein are completely reduced in size until the hardenable material only seals the leaking and / or damaged area on the inner pipe wall. Portions of the hardenable material that have penetrated through the leak into the outer area of the pipeline and completely or partially fill the cavities located there remain untouched by the milling process.

[0028] After carrying out the method according to the invention, the leaking and / or damaged area on the inner pipe wall is completely sealed by the hardenable material, the area outside the leaking area in the pipe wall is additionally protected from external influences, and all solids previously present in the area of the pipe, such as pipe fragments, soil, stones, dust, etc., are completely removed from the pipe. The cross-section of the pipeline corresponds to the cross-section of the rest of the pipeline. Between the area machined with the milling cutter and the rest of the pipeline, there are no edges or leaks where deposits could form or through which substances from outside could penetrate the pipeline, or through which substances present in the pipeline could escape.

[0029] In a preferred embodiment of the method according to the invention, a PU material is introduced as the curable substance. The PU material can be, for example, a single-component PU material and / or a PU foam.

[0030] Corresponding materials and foams are known to those skilled in the art from other applications. Two-component PU foam has proven particularly advantageous; the components are fed through two hoses from the component storage container into the pipeline and the bellows body. In this embodiment, the two components only mix in the area in the pipeline or bellows body where the PU material is to be introduced. As soon as the PU material has been introduced into the bellows body, the two hoses are pulled out of the bellows body. Once the PU material in the bellows body has hardened, further PU material is introduced via the hoses into the area in front of the bellows body, in the area of the leaky and / or damaged inner pipe wall, until the area of the leaky and / or damaged inner pipe wall is completely filled with PU material.Before the PU material hardens, the two hoses are removed from the pipeline.

[0031] In another embodiment, an epoxy resin is introduced into the bellows body and / or the pipeline as a curable material. Epoxy resins, as defined by the invention, are all synthetic resins containing epoxy groups that, when mixed with a hardener, react to form a thermosetting plastic. After curing, epoxy resins possess good mechanical properties and are particularly suitable for sealing pipelines.

[0032] Furthermore, the invention provides that the hardenable material is introduced into the bellows body and / or the interior of the pipeline by means of a pumping device located outside the pipeline. Particularly in pipelines where the leaking and / or damaged area is far away from the access opening of the pipeline, powerful pumping devices are recommended, with which the hardenable material is pumped from the storage container through hoses into the bellows body and / or the area in front of it. The pumping device ensures that the hardenable material or its components can be quickly and safely transported to the desired location within the pipeline.

[0033] Alternatively, the curable material or its components can also be introduced into the bellows body and / or the interior of the pipeline using a spray device. Spray devices are particularly suitable when using PU foam.

[0034] For shorter distances between the access opening of the pipeline and the leaking and / or damaged area in the inner pipe wall, a spray can can also be used as a spraying device, which uses a propellant gas to transport the PU material through the hose to the place of use within the pipeline.

[0035] In another embodiment, a spray gun is used as the spraying device. To increase the spray gun's efficiency, the spray gun can be operated with compressed air. The spray gun is connected to a compressor, which feeds the compressed air into the spray gun and transports the curable material through the hoses to the point of use within the pipeline.

[0036] A cost-effective design involves a plastic bag for the volume-expanding bellows body. The plastic bag should be sized so that it can be easily inserted into the pipeline when empty and that it seals the pipeline after being filled with a hardenable material. Plastic bags are lightweight and inexpensive to obtain. Furthermore, they can be easily and completely milled out after the inserted material has hardened.

[0037] In an improved embodiment of the method according to the invention, the curable substance is introduced into the interior of the bellows body through at least one hose connection from a pump located outside the pipeline, and the hose connection is withdrawn from the bellows body before curing. This prevents the hose connections in the bellows body from becoming firmly enclosed in the introduced substance after the latter has cured. The hose connection can thus be reused after the curable substance has been introduced into the bellows body and, in particular, can be used to introduce the curable substance into the area of the pipeline that lies upstream of the bellows body in the area of the leaking and / or damaged area.

[0038] In the embodiment of the method according to the invention, in which a two-component PU foam is introduced into the pipeline, it is also provided that a separate hose connection for each of the PU foam components is introduced from a pump located outside the pipeline into the interior of the bellows body, and the hose connections are withdrawn from the bellows body before the substance hardens. The use of separate hose connections ensures that the two components of the PU foam only bond to each other within the bellows body or in the area of the leaky and / or damaged spot on the inner pipe wall, where they react with each other and form the PU foam.The separate hose connection prevents the hardenable substance from reacting within a hose connection and thus preventing the hose line from becoming clogged with the hardenable substance on the section between the access opening of the pipeline and the intended location within the pipeline.

[0039] In an advantageous embodiment of the method according to the invention, an agent that accelerates and / or improves the curing of the material is introduced into the bellows body via an additional hose connection. The hose connection can, for example, consist of a heating hose, through which the curable material is heated and its reaction is accelerated. Alternatively, air or water can also be introduced into the curable material via the hose line if the curable material reacts faster and better with air or water.

[0040] In a further embodiment of the method according to the invention, before positioning the bellows body, a mobile camera is first inserted into the pipeline to inspect the interior of the pipeline and to locate leaks and / or damage on the inner pipe wall. The mobile camera examines the interior of the pipeline to determine the locations of leaks and / or damage to the inner pipe wall. In this way, it is possible to precisely determine where the bellows body is to be positioned within the pipeline and at which points the inner pipe wall is to be repaired using the method according to the invention.

[0041] In a further embodiment of the method according to the invention, the pipeline is rinsed with water after the hardened material and the bellows body have been milled out, in order to remove the milled material from the pipeline. During the milling of the pipeline, the bellows body and the hardened material are crushed in the area of the milling. The resulting milled material then initially settles on the ground in the case of a horizontal pipeline, or on the ground in the case of a vertical or inclined pipeline. Pipeline at the next bend. To prevent the pipe from becoming clogged with the milled debris, pressurized air or water is injected into the pipe to move the milled debris from its deposit in the pipe toward the sewer.

[0042] In another embodiment of the method according to the invention, the milled material is suctioned out of the pipeline using vacuum. In this method, the milled material is not conveyed further along the pipeline, as in the previous method, but rather is suctioned out through the access opening to the pipeline. This method has the advantage that no milled material remains in the pipeline system, thus preventing deposits and / or blockages further along the pipeline system.

[0043] Furthermore, a method according to the invention is described in which, after the hardened material and the bellows body have been milled out, a coating device is introduced into the pipeline. With this coating device, a coating is applied to the inner pipe wall in order to protect the pipeline from further impairments and to improve the flow of the material conveyed through the pipeline. In particular, the method according to the invention is intended to coat the pipeline in the area that was previously machined with the milling machine. In this area, unevenness may still exist on the inner pipe wall. The unevenness can be compensated for by the coating, so that a uniform inner pipe wall is once again created. In addition, the coating provides additional protection for this area of the inner pipe wall.

[0044] In a preferred embodiment of this method, at least one rotating brush head is arranged on the coating device. In this embodiment, the brush head is coated with a coating material. When the coating device is then retracted through the pipeline toward the access opening, the rotating brush head applies the coating material evenly to the inner pipe wall.

[0045] Another method involves a spraying device attached to the coating device. The coating material is applied to the inner pipe wall via this spraying device. If the coating device is slowly withdrawn from the pipeline, the coating material is evenly applied to the inner pipe wall.

[0046] In a preferred embodiment of this coating process, the coating material consists of a curable resin. The resin is applied in liquid form to the inner pipe wall. There, it hardens and forms a smooth and even inner pipe wall. As the epoxy resin cures, a hard and durable coating forms inside the pipe.

[0047] Finally, a method according to the invention is disclosed in which, after milling out the cured material and the bellows body, a fabric hose impregnated with a curable resin is attached to the inner pipe wall in the area of the pipeline that was machined with the milling machine. The resin-impregnated hose is made either of felt or polyester fabric. This hose liner adheres to the inner pipe wall. After it has cured, the hose liner forms the inner wall of the pipeline. The hose liner is inserted into the pipeline using an inversion drum. The inversion drum is a pressure vessel that builds up sufficient pressure to pull the hose liner into the pipeline.

Claims

Patent claims 1. A method for sealing and repairing a leaky and / or damaged spot on the inner wall of a pipeline, comprising the following steps: a) Providing a volume-expandable bellows body b) Positioning the bellows body in the interior of the pipeline behind the area of a leaky and / or damaged spot c) Introducing a hardenable substance into the bellows body until the bellows body fully contacts the inner wall of the pipeline and seals the pipeline d) Hardening of the substance in the bellows body e) Introducing a hardenable substance into the interior of the pipeline until the area between the bellows body and the leaky and / or damaged spot in the pipeline is completely filled f) Hardening of the substance in this area of the interior of the pipeline g) Inserting a milling cutter into the interior of the pipeline, the milling head of which has a diameterwhich is smaller than or equal to the diameter of the pipeline h) milling out the hardened material and the bellows body, 2. Method according to claim 1, characterized in that a PU material is introduced as the curable substance.

3. Method according to claim 2, characterized in that a two-component PU foam is introduced as the PU material.

4. Method according to claim 1, characterized in that an epoxy resin is introduced as the curable substance.

5. Method according to one of the preceding claims, characterized in that the hardenable substance is introduced into the bellows body and / or the interior of the pipeline by means of a pumping device.

6. Method according to one of claims 1 to 4, characterized in that the curable substance is introduced into the bellows body and / or the interior of the pipeline by means of a spraying device.

7. Method according to claim 6, characterized in that the spraying device is a spray can.

8. Method according to claim 7, characterized in that the spraying device is a spray gun.

9. Method according to claim 8, characterized in that the spray gun is operated with compressed air.

10. Method according to one of the preceding claims, characterized in that the bellows body is a plastic bag which is positioned in the interior of the pipeline and into which a hardenable substance is introduced. 11 . Method according to one of the preceding claims, characterized in that the hardenable substance is introduced into the interior of the bellows body through at least one hose connection from a pump located outside the pipeline and the hose connection is the material is pulled out of the bellows body.

12. Method according to claim 3, characterized in that each of the components of the PU foam is introduced into the interior of the bellows body through a respective hose connection from a pump located outside the pipeline and the hose connections are pulled out of the bellows body before the substance hardens.

13. Method according to one of the preceding claims, characterized in that an agent is introduced into the bellows body and / or the pipeline via a further hose connection, which agent accelerates and / or improves the curing of the substance.

14. Method according to claim 13, characterized in that air is introduced into the bellows body and / or the pipeline and into the curable material via the hose connection.

15. Method according to claim 13, characterized in that water is introduced into the bellows body and / or the pipeline and into the curable material via the hose connection.

16. Method according to one of the preceding claims, characterized in that before positioning the bellows body, a mobile camera is inserted into the pipeline in order to examine the interior of the pipeline and to be able to locate leaks and / or damaged areas on the inner wall of the pipeline.

17. Method according to one of the preceding claims, characterized in that after milling out the hardened material and the bellows body, the pipeline is rinsed with water in order to transport the milled material out of the pipeline.

18. Method according to one of claims 1 to 16, characterized in that after milling out the hardened material and the bellows body, the milled material is sucked out of the pipeline by means of negative pressure.

19. Method according to one of the preceding claims, characterized in that after milling out the hardened material and the bellows body, a coating device is introduced into the pipeline and a coating is applied to the inner pipe wall at least in the area of the pipeline which was machined with the milling machine.

20. Method according to claim 19, characterized in that at least one rotating brush head is arranged on the coating device, via which a coating material is applied to the inner wall of the pipe.

21. Method according to claim 19, characterized in that a spray device is arranged on the coating device, via which a coating material is applied to the inner wall of the pipe.

22. Method according to one of claims 19 to 21, characterized in that a coating of a curable resin is applied.

23. Method according to one of claims 1 to 19, characterized in that after milling out the hardened material and the bellows body, a fabric hose impregnated with a hardenable resin is attached to the inner wall of the pipe in the area of the pipe which was machined with the milling machine.